amt: drop unexpected query message

AMT gateway interface should not receive unexpected query messages.
In order to drop unexpected query messages, it checks nonce.
And it also checks ready4 and ready6 variables to drop duplicated messages.

Fixes: 19284cc854b3 ("amt: add data plane of amt interface")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

diff --git a/drivers/net/amt.c b/drivers/net/amt.c
index 2d007c5c546362a917fd0083c889c839b43c6f5f..8dc7b8f258c89e524aa6cd5d5ffc8e44f9d386ee 100644 (file)
--- a/drivers/net/amt.c
+++ b/drivers/net/amt.c
@@ -967,8 +967,11 @@ static void amt_event_send_request(struct amt_dev *amt)
                goto out;
        }
 
-       if (!amt->req_cnt)
+       if (!amt->req_cnt) {
+               WRITE_ONCE(amt->ready4, false);
+               WRITE_ONCE(amt->ready6, false);
                get_random_bytes(&amt->nonce, sizeof(__be32));
+       }
 
        amt_send_request(amt, false);
        amt_send_request(amt, true);
@@ -2353,6 +2356,9 @@ static bool amt_membership_query_handler(struct amt_dev *amt,
        if (amtmq->reserved || amtmq->version)
                return true;
 
+       if (amtmq->nonce != amt->nonce)
+               return true;
+
        hdr_size -= sizeof(*eth);
        if (iptunnel_pull_header(skb, hdr_size, htons(ETH_P_TEB), false))
                return true;
@@ -2367,6 +2373,9 @@ static bool amt_membership_query_handler(struct amt_dev *amt,
 
        iph = ip_hdr(skb);
        if (iph->version == 4) {
+               if (READ_ONCE(amt->ready4))
+                       return true;
+
                if (!pskb_may_pull(skb, sizeof(*iph) + AMT_IPHDR_OPTS +
                                   sizeof(*ihv3)))
                        return true;
@@ -2389,6 +2398,9 @@ static bool amt_membership_query_handler(struct amt_dev *amt,
                struct mld2_query *mld2q;
                struct ipv6hdr *ip6h;
 
+               if (READ_ONCE(amt->ready6))
+                       return true;
+
                if (!pskb_may_pull(skb, sizeof(*ip6h) + AMT_IP6HDR_OPTS +
                                   sizeof(*mld2q)))
                        return true;